Glasses that provide an additional feature; an overlay that lets you see information and graphics along with the real-world view.

It would be great to be able to see more information along with your view of the actual world. Like looking a building, and seeing all the companies and people that work in it. And you could use it for other things.

There's also a brief printed note on paper. "Attach to front of building above eye level facing the street. When attached, initiate pairing with your phone to 'unnamed device 1142.' Passcode is 46hg52Q. Once paired, dial ##*49##*, and leave the area..."

Bloody typical. You pocket the bugging device, or whatever it is, key the co-ordinates into your specs, and let the overlay guide you along the pavement towards the target building..."

He passes you a pair of heavy, black-rimmed military spectacles and a ruggedized phone... You put the glasses on and boot them. There's a brief flicker as they check your irises against their preloaded biometrics, then the world outside the BMW is drenched in unfamiliar information all the way to the horizon...

This sort of augmented reality device can be seen in a slightly more compact form in the smart contact lenses from Fast Times at Fairmont High by Vernor Vinge, and somewhat earlier, the DreamTime contacts from Niven and Barnes' 1992 novel The California Voodoo Game.